Self-threading motion picture machine



June 26, 1962 F. A. LUNZER 3,

SELF-THREADING MOTION PICTURE MACHINE Filed Nov. 50, 1960 3 Sheets-Sheet1 i Maul-m illllllll-nll L\\ f i v mmvron m FZEDEE/C ,4. 10/7252 i Y 92F5 22 m June 26, 1962 F. A. LUNZER SELF-THREADING MOTION PICTURE MACHINEFiled Nov. 30, 1960 5 Sheets-Sheet 2 INVEN TOR.

F2D2l6 ,9. AU/YZER lrrop/vaks June 26, 1962 F. A. LUNZER SELF-THREADINGMOTION PICTURE MACHINE 3 Sheets-Sheet 3 Filed Nov. 30, 1960 m T m W.

3,040,945 SELF-THREADING MOTION PECTURE MACHINE Frederic A. Lunzer, NewYork, N.Y., assignor to De Jur- Amsco Corporation, Long Island City,N.Y., a corporation of New York Filed Nov. 30, 1960, Ser. No. 72,688 4Claims. (Cl. 226-91) The present invention relates to an improvedselfthreading motion picture machine. 7

In motion picture machines provided with self-threading mechanisms, thefilm strip is automatically threaded through the machine, the film beingadvanced from the upper film sprocket, through the film gate (and theintermittent drive) to the lower film sprocket, a loop being formed inthe film between each sprocket and the film gate by a loop-former. Upperand lower loopformers are according mounted for movement between aloop-forming position assumed during loop forming and a retractedposition (for out of frictional contact with the film) assumed for andheld during the running of the film in the subsequent operation of themachine. Latching means are provided for latching the loop-formers intheir loop-forming position; and means is provided operated uponcompletion of the film threading step for unlatching the latching meansto thereby cause the loopformers to move to their retracted position.

The prime object of the present invention centers about the constructionand mechanical design of a selfthreading mechanism of this nature andfunctioning as above referred to, characterized by the followingstructural and functional improvements:

(1) The loop-formers, constructed and inter-meshed for movement inunison between their loop-forming and retracted positions, are movablefrom a normal retracted position to their loop-forming position manuallyby directly engaging and moving either (and preferably the upper)loop-former;

(2) The loop-formers are latched in their loop-forming position by alatching means associated directly with the lower loop-former andarranged between the same and the lower sprocket, designed so that whenthe film is advanced and engaged by the lower sprocket, the film engagesand trips the latching means, thereby releasing the loop-formers forreturn movement to their retracted position out of frictional contactwith the film; and

(3) Film guides are associated with the sprockets and the loop-formers,movable relative thereto to permit any removal of the film from themachine that may be desirable or made necessary before total passage ofthe film is achieved; and the lower film guide is so related to thelatching means that movement of the lower film guide will also effectthe tripping of the latching means.

A further object of the invention is the provision of an improvedself-threading machine of this character in which all of the describedparts are combined andinterrelated to produce a machine havingcompactness, an economy of parts, accessibility of parts and a facilityof manipulation and operation.

To the accomplishment of the foregoing objects and such other objects asmay hereinafter appear the present invention relates to theself-threading motion picture machine as sought to be defined in theappended claims and as described in the following specification andshown in the accompanying drawings, in which:

FIG. 1 is a side elevational view of the self-threading mechanism orapparatus of the present invention as ap plied to a motion pictureprojector and showing the parts in the position for loading orself-threading the film strip;

FIG. 2 is a similar view thereof shown on a somewhat enlarged scale buttaken in cross-section in the plane of States Patent HQQ the line 22 ofFIG. 3, and showing the parts in the position for the operation of themachine following the self-threading step;

FIG. 3 is a view of FIG. 2 taken in cross-section in the planes of thebroken line 33;

FIG. 4 is a view taken on an enlarged scale of the latching means andits relation to the lower loop former;

FIG. 5 is a view of FIG. 4 taken in cross-section in the planes of thebroken line 5-5; and

FIG. 6 is a perspective view of the parts of the selfthreading mechanismof the present invention showing the parts in an exploded condition.

Referring now more in detail to the drawings and having reference firstto FIGS. 1 to 3 thereof, the self-threading mechanism of the inventionis shown applied to a motion picture projector, the related parts ofwhich comprise a framework providing a vertical supporting wall 10, atransversely arranged supporting wall 12, a film gate mount 14 hingedlyconnected at 16 to the transverse wall 12, the film gate mount carryingthe objective or lens mount 18. The motion picture machine is as usualprovided with means for feeding and guiding a film strip through themachine comprising an upper film sprocket 20, a lower film sprocket 22and the film gate with which latter is associated the customaryintermittent film drive means (not shown).

In self-threading mechanisms the film strip, such as the film 24 whenpresented as indicated in FIG. 1 to the upper film sprocket, is advancedfrom the upper film sprocket through the film gate (and the intermittentdrive) to the lower film sprocket 22, a loop being formed in the filmbetween each sprocket and the film gate by a loop-former. Accordinglyupper and lower loop-formers 26 and 28 are provided, mounted formovement between a loop-forming position shown in FIG. 1 of the drawingsduring the loopforming step and a retracted position shown in FIG. 2 ofthe drawings, which latter positioning .is assumed for the continuedrunning of the film in the operation of the machine. In the loop-formingstep, loops are provided in the film strip 24 as shown in FIG. 2, andwhen the loopformers are moved to their retracted position, theloopformers are removed out of frictional contact with the film.Associated with the loop-formers are the upper and lower film guides 30and 32 pivotally movable with reference to the sprockets 20 and 22 aboutthe axes 34 and 36 respectively. The loop-formers and film guides areshaped and contoured as shown in FIGS. 1 to 3 (and particularly depictedin FIG. 6 of-the drawings) and these parts are preferably made of asuitable plastic material molded to these shapes and contours, theplastic material being preferable such as to produce transparentproducts.

Means are provided for interconnecting the loop-formers 26 and 28 formoving the same in unison between their loop-forming (film threading)and retracted positions; and for this purpose the loop-formers includeintermeshing gear segments, one fixed to each loop-former. Accordinglymetal segments 38 and 40 shaped as best shown in FIG. 6 of the drawingsare afiixed respectively to the loop-formers 26 and 28 (in a manner tobe described hereinafter) and these segments are formed with theintermeshing gear teeth 42 and 44. By means of this constructionmovement of either of the loop-formers will impart oted film guides 30and 32 are also resiliently urged by being spring loaded to their normalmachine operating positions as depicted in both FIGS. 1 and 2 of thedrawings. To accomplish the spring loading of both the loop-formers andthe film guides means is provided for 'so resiliently interconnectingeach loop-former to its associated film guide as to accomplish thesefunctions. This is accomplished by means of the upper spring 46 and thelower spring 48, these parts being best depicted in FIG. 6 of thedrawings, each of which springs is anchored at its opposite ends to aloop-former and a film guide in a manner clearly shown in FIG. 2 andwhich will be further detailed hereinafter. By means of thisconstruction and arrangement it will be seen that the film-formers willnormally assume, under the action of the springs 46 and 48, theretracted position shown in FIG. 2, that the loopformers may be moved totheir film threading position by directly manually engaging either theupper loop-former 26 or the lower loop-former 2'8 and moving the sameagainst the tension of the springs 46 and 48, that the film guides 30and 32 will be normally resiliently held by the same springs in theiroperative film guiding positions shown in FIGS. 1 and 2, and that thesefilm guides 30 and 32 may be manually moved against the tensioning ofthe springs to positions away from the sprockets 20 and 22, the latterto permit any removal of the film from the machine that may be desirableor made necessary before total passage of the film through the machineis achieved, the movement of the lower film guide 32 against the actionof the spring 48 being also desirable for effecting a tripping oflatching means hereinafter further described.

When the loop-formers are moved to their film threading position, theyare automatically latched in that position; and when the film hascompleted its self-threading step, the loop-formers are unlatched forreturn movement to their retracted position. The latching means which isprovided for this purpose is associated with the lower loopformer and ismade movable between latching and unlatching positions and is arrangedso that it is spring loaded for movement to its latching position. Thislatching means 50 comprises a member configured as best shown in FIG. 6of the drawings, pivotally mounted at 52 on the vertical projector wall10, the said member being formed with an element 54 projecting into thepath of the film strip (and projecting for this purpose toward and intothe sprocket 22 as best shown in FIGS. 4 and the said latching meansbeing also provided with a part such as a tooth 56 projecting inwardlytherefrom, which tooth is adapted for engaging a part of the lowerloop-former, and more particularly a part of the lower gear segment 40thereof for latching the same; and for this purpose the lower gearsegment 40 is provided in an arcuate slot 58 thereof with a cam ordepressed part 60 for lodging the tooth 56 in its latching position. Thelatching means 50 is spring loaded by means of a spring 62 anchored atone end to a peg 63 and at its other end to a hook 64 formed in the.latching member. The upper gear segment 38 is also formed with anarcuate slot 66. By means of this construction it will be seen that whenthe loop-formers are moved to their film threading position (FIG. 1),the 'gear segments 38 and 40 are moved in unison to the po' sition shownin FIGS. 1 and 4 and the latching member 50 urged by the spring 62 movesto the position best shown in FIGS. 1 and 4, in which position thelatching tooth 56 engages the cam or depression 60, thereby latching thegear segments and the loop-formers in the film threading position. Itwill be further seen that when the self-threaded film reaches the lowersprocket 22, the film engages the projecting. element 54, therebylifting the latching member 50 to the position shown in FIG. 2 of thedrawings, in which position the latching tooth 56 is removed out of thepath of the depression 60, and thereby the gear segments and theloop-formers to which they are attached, are automatically released formovement to their retracted position as shown in FIG. 2.

As heretofore stated, the lower film guide 32 is so related to thelatching means that movement of the lower film guide will also effectthe tripping of the latching means. This is accomplished by providingthe latching means with a transverse part 68' which is received by anopening 70 formed in an inner wall of the guide 32 as best shown inFIGS. 4 and 5 of the drawings. Thereby when the film guide 32 is lifted(against the action of the spring 48), the part 68 of the latchingmember will be engaged by the lower wall of the opening 70 and willthereby be moved to a tripping position.

Preferably to discourage inserting the film strip in the machine whenthe loop-formers are not in their film threading position, a guardmember 72 is provided shaped as best indicated in FIG. 6, andindependently pivoted about the axis of the upper sprocket 20 but whichis arranged to be movable from the guarding position shown in FIG. 2 tothe ungarding position shown in FIG. 1 by the movement of the upperloop-former 26. A guard roll 74 is mounted Within the guard member 72.By means of the independent movement of the guard member it may belifted above the position shown in FIG. 1, to permit freedom ofinsertion of the film into the machine. However, when the parts assumethe position shown in FIG. 2, the guard member is dropped to thecondition depicted in FIG. 2.

FIG. 6 shows the separate parts which make up the self-threadingmechanism and depicts the manner of assembling these parts. The gearsegment 38 is attached to the loop-former 26 by means of the screws 76;the sprocket 20 is mounted by means of its shaft 78 in the bearing 80provided in the vertical supporting wall 10; the upper film guide 30 issecured to the wall 10 pivotally by means of the screw bolt 82; thespring 46 is anchored at its opposite ends by means of the pegs 84 and86 in turn fixed to the guide 30 and loop-former 26; and the gearsegment 38 as well as the guard member 72 are pivotally mounted on theferrule 88, and held in position by the collar 89 (see FIG. 3), theparts being otherwise assembled as indicated by the dot and dash linesshown associated with these parts. Similarly the gear segment 40 isattached to the loop-former 28' by means of the screws 90; the lowersprocket 22 is mounted by means of its shaft 92 in the bearing 94provided in the wall 10; the lower film guide 32 is secured to the wall10 pivotally by means of the screw or bolt 96; the spring 48 is anchoredat its opposite ends by means of the pegs 98 and 100 in turn fixed tothe guide 32 and the loop-former 28; and the gear segment "40 ispivotally mounted on the ferrule i102 and held in position by the collar103 (see FIG. 5), the par-ts being other assembled as indicated by thedot and dash lines shown. To these parts is added a lower film guide 104mounted in the boss bearing 106 by means of a bolt 108. A retainingscrew 110 (-FIGS. 1 and 2) is also preferably used to guide the uppergear segment in its movements.

The operation of the self-threading mechanism of the present invention,the interrelation of the parts thereof, their related functioning andthe described advantages obtained in the improved construction suppliedwill in the main be fully apparent from the above description thereof.It will be further apparent that many changes may be made thereinwithout departing from the spirit of the invention defined in thefollowing claims.

I claim:

1. A self-threading motion picture machine, in combination with meansfor feeding and guiding a film strip through the machine, mechanism forforming upper and lower film loops in the machine comprising a pivotallymounted upper loop-former and a pivotally mounted lower loop-former,said loop-formers including intermeshing segments, one fixed to eachloop-former, interconnecting the loop-formers for moving the same inunison between a film threading position and a retracted position, thesaid loop-formers being spring loaded for movement to their retractedposition and being manually movable against the spring loading to theirfilm threading position, a latching means associated with said lowerloop-former movable between latching and unlatching positions and beingspring loaded for movement to its latching position, said latching meanshaving an element projecting into the path of the film strip and havinga part for then engaging a part of the lower loop-former to latch thesame in its film threading position, the said element projecting intothe path of the film strip being adapted to be engaged by the film stripfor moving the latching means to its unlatching position and therebyrelease said loop-formers for movement in unison to their retractedposition, an upper film guide associated with the upper loop former, alower film guide associated with the lower loop former and movable abouta pivot relative thereto, and means forming part of said latching meansextending into the path of movement of said lower film guide wherebymanual movement of said lower film guide about its pivot will move thelatching means to an unlatching position.

2. In the self-threading motion picture machine of claim 1, a springinterconnecting each loop-former to its associated film guide, saidspring defining the spring loading of the loop-former and acting forspring loading the film guide.

3. A self-threading motion picture machine for a motion picture machinein combination with upper and lower sprockets and a film gate forfeeding and guiding a film strip through the machine, mechanism forforming a film loop between each sprocket and the film gate comprisingan upper loop-former mounted for pivotal movement about the axis of theupper sprocket, a lower loop-former mounted for pivotal movement aboutthe axis of the lower sprocket, said loop-formers including intermeshingsegments, one fixed to each loop-former, interconnecting theloop-formers for moving the same in unison between a film threadingposition and a retracted position, the said loop-formers being manuallymovable to their threading position and being spring loaded for movementto their retracted position, a latching means arranged between the lowersprocket and the lower loop-former movable between latching andunlatching positions and spring loaded for movement to its latchingposition, said latching means having an element projecting toward thelower sprocket and into the path of the film strip and having a part forthen engaging a part of the lower loop-former to latch the same in itsfilm-threading position, the engagement of the film strip with saidelement causing the latching means to move to unlatching position andthereby releasing said loop-formers for movement in unison to theirretracted position, an upper film guide associated with the uppersprocket and mounted on a pivot located between said upper sprocket andthe film gate, a lower film guide associated with the lower sprocket andmounted on a pivot located between the lower sprocket and the film gate,and means forming part of said latching means extending into the path ofmovement of said lower film guide whereby manual movement of said lowerfilm guide about its pivot will move the latching means to an unlatchingposition.

4. In the self-threading machine of claim 3, a spring interconnectingeach loop-former .to its associated film guide, said spring defining thespring loading of the loop-former and acting for spring loading the filmguide.

References Cited in the file of this patent UNITED STATES PATENTS2,420,587 Dietrich May 13, 1947 2,832,258 Chevallaz Apr. 29, 19582,983,416 Hanken et al May 9, 196 1

